This application is the U.S. national phase of international application PCT/NO99/00098 filed Mar. 23, 1999 which designated the U.S.
The present invention relates to a multipurpose air conditioning apparatus for ventilation, heating of air and cooling of air, comprising fan assemblies, a compressor, condenser, evaporator, liquid/gas circuit, throttling means, air inlets and air outlets. The apparatus is adapted so as to make the functions of the condenser and the evaporator interchangeable for heating of air and cooling of air respectively, by making the liquid flow in the liquid/gas circuit through the condenser, evaporator and throttling means reversible according to requirements.
Further, the invention relates to a method of multipurpose conditioning of indoor air by means of the air conditioning apparatus above.
Further, reference is made to the later description of FIG. 1, which shows the state of the art.
The term xe2x80x9cair conditioningxe2x80x9d will in this context be taken to mean heating of air, cooling of air and ventilation.
At present, several possibilities exist for air conditioning combined with energy saving, and various equipment in the form of air conditioners is commercially available. One possibility is to install a heat pump. The most ordinary heat pumps today are the so-called split units (reversible air conditioner) and window units, which use air as the energy medium. Some air conditioners are adapted so as to draw energy or heat for the heat pump directly from the ground or a river or the sea. This type of heat pump is normally quite expensive to buy, and the cost of installation is very high.
In the cold parts of the world, it has become more and more common to build houses that are very airtight. Airtight houses require better ventilation, which is provided by the present invention.
It is generally agreed that the use of heat pumps will give the greatest reduction in energy consumption. Thus, there is a continued requirement for improvements in the areas of air conditioning and heat pumps, with regards to both indoor environment (allergy) in the form of ventilation, heat recovery and energy saving. Some countries support this through subsidies.
The present multipurpose air conditioning apparatus provides a completely new generation of air conditioning apparatus, with a number of functions designed to create a healthy and comfortable indoor environment the whole year round, at low costs. The present multipurpose air conditioning apparatus will, amongst other things, provide the following, functions:
1. Ventilation only.
2. Ventilation and heating of water.
3. Heating of water (heat pump air-water).
4. Heating of air (heat pump air-air).
5. Heating of air and ventilation.
6. Heating of air and ventilation at low outdoor temperatures (see point 13).
7. Heating of air (water-air).
8. Cooling of air (xe2x80x9cair conditioningxe2x80x9d).
9. Cooling of air with ventilation.
10. Cooling of air, heating of water and ventilation.
11. Cooling of air and heating of water.
12. Cooling of air/ventilation in a room; heating/ventilation in an other room.
13. Rapid defrosting without disruption of the air flow (see point 6).
In addition, a number of other factors may be controlled, such as the pressure conditions in the room.
What distinguishes the apparatus is the number of available functions, and the simple manner in which the switching from function to function is accomplished. Further, the apparatus may be run at optimum performance at any indoor and outdoor conditions, both with regards to performance and energy conservation.
The air conditioning apparatus disclosed herein is based on a principle that has been developed for use with a number of various applications, such as: mobile air conditioners, window units, central units, compact units and split units. The units may be large or small, depending on the requirements.
When used for ventilation only, at comfortable outdoor temperatures, the apparatus may be used purely as a ventilating fan, optionally with means of air filtering
By using infinitely variable fans in the two main units, called Main and Annex respectively, the indoor air pressure may be set to overpressure, balanced pressure or underpressure for all functions. Overpressure will be particularly desirable for those who suffer from allergies, underpressure for areas of contagion, such as hospitals, and balanced pressure in most other areas, such as living areas.
In connection with heating or cooling of air, it is possible to choose ventilation as an additional feature. When the outdoor temperature is low, it may be advantageous to mix the outdoor air and indoor air before it passes through the apparatus . By so doing, it is possible to make use of the energy contained in the warm indoor air, in order to improve the efficiency of the apparatus.
Whether the apparatus is run to heat air or cool it, it will be profitable to heat water at the same time, by making use of the excess heat.
According to the present invention, there is provided an air conditioning apparatus of the aforementioned type, characterised in that it comprises at least two separate units, Main and Annex, each with an air heat exchanger that acts as a combined condenser/evaporator, a fan assembly, a fresh air inlet, an indoor air inlet and a mixing chamber upstream of the heat exchangers, an air outlet downstream of the heat exchangers and means of redirecting the air flows, in addition to which the apparatus also includes bypass loops in the liquid/gas circuit with closing and throttling means.
Preferably, the circulation of liquid through the condenser and the evaporator is reversible by way of a four-way valve.
Advantageously, the liquid/gas circuit may be redirected to a heat exchanger in which the other medium is water, for the additional function of heating water, and this is preferably the part of the liquid/gas circuit that is located downstream of the compressor.
The two or more separate units may have a common compressor, and are connected via the liquid/gas circuit.
The units may be designed to be spaced apart, for instance at opposite ends of a room or on different floors, Annex advantageously placed high and Main advantageously placed low.
Alternatively, the apparatus may be a compact unit, with the units placed close together, either on top of each other or next to each other.
Preferably, the means of redirecting the air circulation include a through-apparatus channel between the room and the outside, with a rotatable damper for air redirection. The means of closing off the air circulation may include an air intake with a damper for indoor air, and an air intake with a damper for outdoor air and a 0-100% mixture of outdoor and indoor air.
The throttling means may be in the form of a capillary tube.
According to the present invention, there is also provided a method of the type described initially, which is characterised in that outdoor air, indoor air or a mixture of the two is directed to the upstream side of a combined condenser/evaporator, is drawn through the condenser/evaporator by the fan assembly, and displaced further on the downstream side of the condenser/evaporator, towards the room, the surroundings or both.